Polycrystalline silicon cold hydrogenation high-pressure emergency protection device

Abstract

The utility model provides a polycrystalline silicon cold hydrogenation high-pressure emergency protection device, and relates to the technical field of polycrystalline silicon. The device comprises a nitrogen source, a second buffer tank is communicated with the pressurized nitrogen source, one end of a gas inlet pipe is communicated with the second buffer tank, a valve assembly is arranged on the gas inlet pipe, the other end of the gas inlet pipe is communicated with a polycrystalline silicon cold hydrogenation synthesis system, and the pressure in the second buffer tank is the same as the working pressure of the polycrystalline silicon cold hydrogenation synthesis system. And the valve assembly is automatically opened and closed according to the pressure difference between the second buffer tank and the polycrystalline silicon cold hydrogenation synthesis system. When leakage or fire accidents which cannot be cut off occur in the system, nitrogen can enter the system as soon as possible so as to improve the safety of the system.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of polysilicon, specifically relates to a polysilicon cold hydrogenation high pressure emergency protection device. BACKGROUND

[0002] At present, manufacturers usually select improved siemens method to produce polysilicon, and the silicon tetrachloride, hydrogen chloride and hydrogen generated in the reduction production of polysilicon are all recycled by a cold hydrogenation device, silicon powder is added to a fluidized bed reactor, and under the action of high temperature and high pressure, the raw material trichlorosilane needed for producing polysilicon is produced, and the closed circuit circulation of the polysilicon process is realized.

[0003] In the existing polysilicon cold hydrogenation synthesis system, when the system cannot be isolated from leakage or fire events, the system pressure can only be reduced from 2.5MPa to below 0.6MPa (usually 2-3 hours are needed to reduce the pressure to below 0.6MPa), and then nitrogen can be introduced into the system. In this process, due to high temperature and high pressure, derivative accidents are prone to occur. UTILITY MODEL CONTENTS

[0004] The utility model aims at developing a polysilicon cold hydrogenation high pressure emergency protection device which can introduce nitrogen into the system as soon as possible to improve the safety of the system when the system cannot be isolated from leakage or fire events.

[0005] The utility model is realized through the following technical scheme:

[0006] A polysilicon cold hydrogenation high pressure emergency protection device, comprising:

[0007] A nitrogen source;

[0008] A second buffer tank in communication with the pressurized nitrogen source;

[0009] An air inlet pipe in communication with the second buffer tank at one end;

[0010] A valve assembly arranged on the air inlet pipe;

[0011] The other end of the air inlet pipe is in communication with a polysilicon cold hydrogenation synthesis system, the pressure in the second buffer tank is the same as the working pressure of the polysilicon cold hydrogenation synthesis system, and the valve assembly automatically opens and closes according to the pressure difference between the second buffer tank and the polysilicon cold hydrogenation synthesis system.

[0012] Optionally, the nitrogen source is in communication with a first buffer tank, the first buffer tank is in communication with a compressor, and the second buffer tank is in communication with the compressor.

[0013] Optionally, the polysilicon cold hydrogenation synthesis system comprises a second heat exchanger, a first heat exchanger and a separator connected in sequence, and a pipeline between the first heat exchanger and the separator is communicated with the gas inlet pipe.

[0014] Optionally, the valve assembly comprises a first valve arranged on the gas inlet pipe.

[0015] Optionally, a second valve is further arranged on the gas inlet pipe, and the first valve and the second valve are arranged in sequence according to the gas flow direction.

[0016] Optionally, a vent pipe is communicated with the gas inlet pipe between the first valve and the second valve.

[0017] Optionally, a third valve is arranged on the vent pipe.

[0018] Optionally, the first valve, the second valve and the third valve are all solenoid valves.

[0019] Optionally, a first pressure gauge is arranged on the second buffer tank, a second pressure gauge is arranged on the pipeline between the first heat exchanger and the separator, and the first pressure gauge and the second pressure gauge are interlocked controlled with the first valve, the second valve and the third valve.

[0020] The utility model has the advantages of:

[0021] The utility model adds a set of 2.5MPa high-pressure nitrogen system, which is communicated with the polysilicon cold hydrogenation synthesis system, and uses the pressure difference between the system pressure and the high-pressure nitrogen pressure as the judgment condition, and uses the valve assembly to cut off, which not only avoids the material gas from leaking into the nitrogen when the system pressure is higher than the high-pressure nitrogen system, but also reduces the emergency time of system pressure reduction, and the nitrogen injection time is reduced from 2-3 hours to 0.5 hours, which greatly reduces the possibility of derivative accidents caused by the system leakage or fire accidents that cannot be cut off, and improves the safety of the system. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0023] Figure 1 The utility model is a structural diagram.

[0024] Reference numerals in the attached diagram: 1. Nitrogen source; 2. First buffer tank; 3. Compressor; 4. Second buffer tank; 5. First pressure gauge; 6. First valve; 7. Third valve; 8. Second valve; 9. Separator; 10. Second pressure gauge; 11. First heat exchanger; 12. Second heat exchanger; 13. Inlet pipe; 14. Vent pipe; 15. Reactor; 16. Electric heater; 17. Steam heater. Detailed Implementation

[0025] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0026] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0027] The embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0028] like Figure 1 As shown, this utility model discloses a high-pressure emergency protection device for polycrystalline silicon cold hydrogenation, including a first buffer tank 2, a compressor 3, and a second buffer tank 4 connected in sequence. A nitrogen source 1 is connected to the first buffer tank 2, and the nitrogen supplied by the nitrogen source 1 passes through the first buffer tank 2, the compressor 3, and the second buffer tank 4 in sequence.

[0029] The polycrystalline silicon cold hydrogenation synthesis system includes a reactor 15, a second heat exchanger 12, a first heat exchanger 11, a separator 9, and a steam heater 17 connected in sequence. The steam heater 17 is then connected to the first heat exchanger 11, the second heat exchanger 12, an electric heater 16, and the reactor 15 in sequence.

[0030] The second buffer tank 4 is equipped with an air inlet pipe 13, and the pipeline between the first heat exchanger 11 and the separator 9 is connected to the air inlet pipe 13.

[0031] The air inlet pipe 13 is provided with a valve assembly, which comprises a first valve 6 and a second valve 8 arranged in sequence along the air flow direction on the air inlet pipe 13, and a vent pipe 14 is communicated between the first valve 6 and the second valve 8 on the air inlet pipe 13, and the vent pipe 14 is provided with a third valve 7; the first valve 6, the second valve 8 and the third valve 7 are all electromagnetic valves.

[0032] The first pressure gauge 5 is arranged on the second buffer tank 4, and the second pressure gauge 10 is arranged on the pipeline between the first heat exchanger 11 and the separator 9; the first pressure gauge 5 and the second pressure gauge 10 are interlocked with the first valve 6, the second valve 8 and the third valve 7; the reading P1 of the first pressure gauge 5 is the pressure of the nitrogen gas in the second buffer tank 4 after pressurization, the reading P2 of the second pressure gauge 10 is the pressure of the polysilicon cold hydrogen synthesis system, and ΔP = P1-P2; when ΔP≤100Kpa, the first valve 6 and the second valve 8 are closed, and the third valve 7 is opened; when ΔP>100Kpa, the first valve 6 and the second valve 8 are opened, and the third valve 7 is closed, and the nitrogen gas enters the system to perform emergency nitrogen replacement; the pressure of the nitrogen gas after pressurization by the compressor 3 is generally 2.5Mpa, and the system pressure is generally 2.5Mpa; when the system has an unblockable leakage or fire event, the system pressure is reduced by more than 100Kpa based on 2.5Mpa, so that the nitrogen gas can be introduced into the system to perform emergency nitrogen replacement.

[0033] The utility model increases a set of 2.5MPa high pressure nitrogen gas system, makes it with polysilicon cold hydrogen synthesis system intercommunication, with the pressure difference of system pressure and high pressure nitrogen gas pressure as the judging condition, separates with valve assembly, avoids the material gas of the system pressure higher than high pressure nitrogen gas system when from entering nitrogen gas, also reduces the emergency time of system pressure reduction processing, the time of system nitrogen introduction reduces to 0.5 hours from 2-3 hours, greatly reduces the possibility of derivative accident when the system has unblockable leakage or fire accident, improves the safety of system.

[0034] The above embodiment is only a preferred embodiment of the utility model, and does not limit the technical scheme of the utility model, and as long as the technical scheme can be realized on the basis of the above embodiment without creative labor, it should be considered that it falls within the protection scope of the utility model patent.

Claims

1. A high-voltage emergency protection device for polycrystalline silicon cold hydrogenation, characterized in that, include: Nitrogen source; The second buffer tank is connected to the pressurized nitrogen source; The intake pipe has one end connected to the second buffer tank. Valve assembly, located on the intake pipe; The other end of the air inlet pipe is connected to the polycrystalline silicon cold hydrogenation synthesis system. The pressure inside the second buffer tank is the same as the working pressure of the polycrystalline silicon cold hydrogenation synthesis system. The valve assembly automatically switches on and off based on the pressure difference between the second buffer tank and the polycrystalline silicon cold hydrogenation synthesis system.

2. The polycrystalline silicon cold hydrogenation high-voltage emergency protection device according to claim 1, characterized in that, The nitrogen source is connected to the first buffer tank, the first buffer tank is connected to the compressor, and the second buffer tank is connected to the compressor.

3. The polycrystalline silicon cold hydrogenation high-voltage emergency protection device according to claim 2, characterized in that, The polycrystalline silicon cold hydrogenation synthesis system includes a second heat exchanger, a first heat exchanger, and a separator connected in sequence, with the pipeline between the first heat exchanger and the separator connected to the inlet pipe.

4. The polycrystalline silicon cold hydrogenation high-voltage emergency protection device according to claim 3, characterized in that, The valve assembly includes a first valve disposed on the intake pipe.

5. The polycrystalline silicon cold hydrogenation high-voltage emergency protection device according to claim 4, characterized in that, The intake pipe is also equipped with a second valve, and the first valve and the second valve on the intake pipe are arranged in sequence according to the airflow direction.

6. The polycrystalline silicon cold hydrogenation high-voltage emergency protection device according to claim 5, characterized in that, An air vent pipe is connected to the air inlet pipe between the first valve and the second valve.

7. The polycrystalline silicon cold hydrogenation high-voltage emergency protection device according to claim 6, characterized in that, The vent pipe is equipped with a third valve.

8. The polycrystalline silicon cold hydrogenation high-voltage emergency protection device according to claim 7, characterized in that, The first valve, the second valve, and the third valve are all solenoid valves.

9. The polycrystalline silicon cold hydrogenation high-voltage emergency protection device according to claim 8, characterized in that, The second buffer tank is equipped with a first pressure gauge, and the pipeline between the first heat exchanger and the separator is equipped with a second pressure gauge. The first pressure gauge, the second pressure gauge, the first valve, the second valve, and the third valve are interlocked for control.

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